<span>pH = pKa + log ([R-]/[RH])
Where pH is the pH of the buffer, [R-] is the concentration of the basic species, and [RH] is the concentration of the acidic species.
At pH 2.4, the amino group on glycine (pKa = 9.6) will be, for accounts and purposes, 100% protonated. This means our buffer will be dealing with the two ionic forms of the carboxyl group (pKa = 2.4).
When pH = pKa, the two species are in equilibrium. This can be seen using the HH equation:
2.4 = 2.4 + log ([R-]/[RH])
0 = log ([R-]/[RH])
1 = ([R-]/[RH])
[RH] = [R-]
Now we add in another equation, our conservation of mass.
M = [RH] + [R-]
where M is the molarity of the buffer
But since [RH] = [R-]:
M = 2 [RH]
0.2 = 2 [RH]
And we wind up with:
[RH] = [R-] = 0.1 M
Now to figure out the moles of each needed, we multiply by the volume of the buffer.
0.1 M * 0.1 L = 0.01 mol
This shows that to make 100 ml of 0.2 M glycine buffer, we'll need 0.01 mol of each species.
0.01 mol of 0.5 M HCl:
0.5 mol HCl / 1 L = 0.01 mol / v
solve for v
v/1 = 0.01 / 0.5 ==> v = 0.02 L or 20 mL
weight of glycine:
MW: 75.07 g/mol
0.01 mol glycine * (75.07g glycine / 1 mol) = 0.75 g glycine
And there's your answer
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To make this buffer you would add 0.75g glycine to 20 mL of 0.5 M HCl and fill with water until a 100mL volume was achieved.</span>
Answer:
<h2>High heels and glittery fashion</h2>
Explanation:
70's was an era of individuality and expression and it was also reflected in the dresses. During 1970's fashion rules were broken and unique outfits were designed . Some of the key style of the decade included peacock revolution, glam rock, hippie and disco. Due to influx of cheap clothing in the market men showcased which group they belonged to by dressing like that.
By middle of the decade men adopted glamorous rock style, this trend was popular in Britain where young men idolised flamboyant musicians such as Freddie Mercury. High heels and glittery clothes were also inspired from rock music. This style included oversized collars, silk scarves , tan leather jackets, frilly satin shirts and shawl-collar tuxedo jackets. By the end of the decade disco style came in with the advent of disco music and the artists associated with them.
Answer: Paper,computer,water bottle,table and chair.
Explanation: I have all of these for school.
Answer:
C
Explanation:
folk singers in 1930s protested the vietnam war
